/* 程序B-3 用于守护进程的处理函数 */
#include <errno.h>         /* for definition of errno */
#include <stdarg.h>        /* ANSI C header file */
#include <stdio.h>
#include <string.h>
#include <sys/syslog.h>
#include <syslog.h>        
#include "ourhdr1.h"

static void log_doit(int, int, const char *, va_list ap);
extern int debug;          /* caller must define and set this:
                              nonzero if interactive, zero if daemon */
/* Initialize syslog(), if running as daemon. */                              
void log_open(const char *ident, int option, int facility)
{
    if(debug == 0)
    {
        open_log(ident, option, facility);
    }
}

/* Nonfatal error related to a system call.
* Print a message with the system's errno value and return. */
void log_ret(const char *fmt, ...)
{
    va_list    ap;
    va_start(ap, fmt);
    log_doit(1,LOG_ERR, fmt, ap);
    va_end(ap);
    return;
}

/* Fatal error related to a system call.
* Print a message and terminate. */
void log_sys(const char *fmt, ...)
{
    va_list    ap;
    va_start(ap, fmt);
    log_doit(1, LOG_ERR, fmt, ap);
    va_end(ap);
    exit(2);
}

/* NonFatal error related to a system call.
* Print a message and terminate. */
void log_msg(const char *fmt, ...)
{
    va_list    ap;
    va_start(ap, fmt);
    log_doit(0, LOG_ERR, fmt, ap);
    va_end(ap);
    return;
}

/* Fatal error related to a system call.
* Print a message and terminate. */
void log_quit(const char *fmt, ...)
{
    va_list    ap;
    va_start(ap, fmt);
    log_doit(0,LOG_ERR, fmt, ap);
    va_end(ap);
    exit(2);
}

/* Print a message and return to caller.
* Caller specifies "errnoflag" and "priority". */
static void log_doit(int errnoflag, int priority, const char *fmt, va_list ap)
{
    int     errno_save;
    char    buf[MAXLINE];

    errno_save = errno;        /* value caller might want printed */
    vsprintf(buf,fmt,ap);
 
    if(errnoflag)
    {
        sprintf(buf+strlen(buf), ": %s", strerror(errno_save));
    }
    strcat(buf, "\n");
    if(debug)
    {
        fflush(stdout);
        fputs(buf, stderr);
        fflush(stderr);
    }
    else 
    {   
        syslog(priority, buf);
        return;
    }
    
}